October 4, 2016Science Daily/University of California - Los AngelesGirls with attention deficit hyperactivity disorder are at higher risk than girls without ADHD for multiple mental disorders that often lead to cascading problems such as abusive relationships, teenage pregnancies, poor grades and drug abuse, psychologists report.

The researchers, who conducted by far the most comprehensive analysis of girls and ADHD, report:

• 37.7 percent of girls with ADHD met criteria for an anxiety disorder, compared with only 13.9 percent of girls without ADHD.• 10.3 percent of girls with ADHD were diagnosed with depression compared with only 2.9 percent without ADHD.• 42 percent of girls with ADHD were diagnosed with oppositional defiant disorder, compared with just 5 percent of girls without it. Oppositional defiant disorder is characterized by angry, hostile, irritable, defiant behavior. To meet the diagnosis for oppositional defiant disorder, a child must display at least four of eight symptoms for at least six months that result in significant academic, social and family problems.• 12.8 percent of girls with ADHD were diagnosed with conduct disorder compared with only 0.8 percent without ADHD. Conduct disorder is similar to oppositional defiant disorder, but with more severe behavioral problems, such as committing violent acts, setting fires and hurting animals.

"We knew the girls with ADHD would have more problems than the girls without ADHD, but we were surprised that conduct disorder and oppositional defiant disorder were at the top of the list, not depression or anxiety," said Steve Lee, a UCLA associate professor of psychology and senior author of the study. "These conduct disorders, more than anxiety and depression, predict severe adult impairments, such as risky sexual behavior, abusive relationships, drug abuse and crime."

Symptoms of ADHD include being easily distracted, fidgeting, being unable to complete a single task and being easily bored. The disorder occurs in approximately 5 percent to 10 percent of children in the United States, and figures in many other industrialized countries with compulsory education are comparable, Lee said. ADHD can begin in pre-school kids and can persist into high school and into adulthood, especially when it's accompanied by oppositional conduct disorder.

The psychologists analyzed 18 studies of 1,997 girls, about 40 percent (796) of whom had ADHD. Most of the girls were between ages 8 and 13. Most ADHD studies focused on boys, or compared girls with ADHD to boys with ADHD -- not to girls without ADHD.

ADHD is often harder to detect in girls than in boys because girls with the disorder may appear disengaged, forgetful or disorganized, and perceived as "spacey" and stay "under the radar" without being referred for assessment and treatment, said lead author Irene Tung, a UCLA graduate student in psychology and National Science Foundation graduate research fellow.